From the viewpoint of simple and inexpensive image production, an inkjet recording method has been used in a variety of printing fields. As the inkjet recording method, there is an UV-curable inkjet method wherein droplets of an UV-curable inkjet ink are landed on a recording medium and then cured by irradiation with ultraviolet rays to form an image. Recently, the UV-curable inkjet method has been attracting attention for its capability of forming images having high rubfastness and adhesiveness even on recording media which lack ink absorbing properties.
However, there have been various drawbacks in improving image quality in the image forming methods using a conventional UV-curable inkjet recording method. For example, there has been a drawback of poor image quality due to failure to prevent combining of neighboring dots (ink gathering) during high-speed recording such as single pass recoding using a line recording head or high speed serial recording.
In order to improve image quality, for example, PTL 1 discloses a method of leveling ink on a substrate, the method including irradiating ink disposed on a first surface of a porous substrate with first radiation emitted by at least one first radiant energy source, the first radiation heating the ink to at least a viscosity threshold temperature of the ink to allow the ink to flow laterally on the first surface to produce leveling of the ink, the ink being heated sufficiently rapidly to make heat transfer from the ink to the substrate sufficiently small during the leveling so that the ink at the substrate interface is cooled to a temperature below the viscosity threshold temperature, thereby preventing any significant ink permeation into the substrate.
Moreover, for example, PTL 2 discloses an inkjet recording process including: forming an image by discharging an actinic radiation-curable ink onto a recording medium; spraying a gas on the image formed on the recording medium; and irradiating the image formed on the recording medium with actinic radiation, in which the actinic radiation-curable ink is solid at room temperature (25° C.).